bpf tools: Introduce 'bpf' library and add bpf feature check
This is the first patch of libbpf. The goal of libbpf is to create a
standard way for accessing eBPF object files. This patch creates
'Makefile' and 'Build' for it, allows 'make' to build libbpf.a and
libbpf.so, 'make install' to put them into proper directories.
Most part of Makefile is borrowed from traceevent.
Before building, it checks the existence of libelf in Makefile, and deny
to build if not found. Instead of throwing an error if libelf not found,
the error raises in a phony target "elfdep". This design is to ensure
'make clean' still workable even if libelf is not found.
Because libbpf requires 'kern_version' field set for 'union bpf_attr'
(bpfdep" is used for that dependency), Kernel BPF API is also checked
by intruducing a new feature check 'bpf' into tools/build/feature,
which checks the existence and version of linux/bpf.h. When building
libbpf, it searches that file from include/uapi/linux in kernel source
tree (controlled by FEATURE_CHECK_CFLAGS-bpf). Since it searches kernel
source tree it reside, installing of newest kernel headers is not
required, except we are trying to port these files to an old kernel.
To avoid checking that file when perf building, the newly introduced
'bpf' feature check doesn't added into FEATURE_TESTS and
FEATURE_DISPLAY by default in tools/build/Makefile.feature, but added
into libbpf's specific.
Signed-off-by: Wang Nan <wangnan0@huawei.com>
Acked-by: Alexei Starovoitov <ast@plumgrid.com>
Cc: Brendan Gregg <brendan.d.gregg@gmail.com>
Cc: Daniel Borkmann <daniel@iogearbox.net>
Cc: David Ahern <dsahern@gmail.com>
Cc: He Kuang <hekuang@huawei.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Kaixu Xia <xiakaixu@huawei.com>
Cc: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Zefan Li <lizefan@huawei.com>
Bcc: pi3orama@163.com
Link: http://lkml.kernel.org/r/1435716878-189507-4-git-send-email-wangnan0@huawei.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2015-07-01 02:13:51 +00:00
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/*
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* Common eBPF ELF object loading operations.
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*
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* Copyright (C) 2013-2015 Alexei Starovoitov <ast@kernel.org>
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* Copyright (C) 2015 Wang Nan <wangnan0@huawei.com>
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* Copyright (C) 2015 Huawei Inc.
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*/
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#ifndef __BPF_LIBBPF_H
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#define __BPF_LIBBPF_H
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2015-07-01 02:13:53 +00:00
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#include <stdio.h>
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2015-07-01 02:14:08 +00:00
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#include <stdbool.h>
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2015-07-01 02:13:53 +00:00
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2015-07-01 02:13:52 +00:00
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/*
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* In include/linux/compiler-gcc.h, __printf is defined. However
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* it should be better if libbpf.h doesn't depend on Linux header file.
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* So instead of __printf, here we use gcc attribute directly.
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*/
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typedef int (*libbpf_print_fn_t)(const char *, ...)
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__attribute__((format(printf, 1, 2)));
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void libbpf_set_print(libbpf_print_fn_t warn,
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libbpf_print_fn_t info,
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libbpf_print_fn_t debug);
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2015-07-01 02:13:53 +00:00
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/* Hide internal to user */
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struct bpf_object;
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struct bpf_object *bpf_object__open(const char *path);
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2015-07-01 02:13:54 +00:00
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struct bpf_object *bpf_object__open_buffer(void *obj_buf,
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2015-08-27 02:30:55 +00:00
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size_t obj_buf_sz,
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const char *name);
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2015-07-01 02:13:53 +00:00
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void bpf_object__close(struct bpf_object *object);
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2015-07-01 02:14:04 +00:00
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/* Load/unload object into/from kernel */
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int bpf_object__load(struct bpf_object *obj);
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int bpf_object__unload(struct bpf_object *obj);
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2015-08-27 02:30:55 +00:00
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const char *bpf_object__get_name(struct bpf_object *obj);
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2015-07-01 02:14:04 +00:00
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2015-07-01 02:14:10 +00:00
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struct bpf_object *bpf_object__next(struct bpf_object *prev);
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#define bpf_object__for_each_safe(pos, tmp) \
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for ((pos) = bpf_object__next(NULL), \
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(tmp) = bpf_object__next(pos); \
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(pos) != NULL; \
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(pos) = (tmp), (tmp) = bpf_object__next(tmp))
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2015-07-01 02:14:08 +00:00
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/* Accessors of bpf_program. */
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struct bpf_program;
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struct bpf_program *bpf_program__next(struct bpf_program *prog,
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struct bpf_object *obj);
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#define bpf_object__for_each_program(pos, obj) \
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for ((pos) = bpf_program__next(NULL, (obj)); \
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(pos) != NULL; \
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(pos) = bpf_program__next((pos), (obj)))
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typedef void (*bpf_program_clear_priv_t)(struct bpf_program *,
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void *);
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int bpf_program__set_private(struct bpf_program *prog, void *priv,
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bpf_program_clear_priv_t clear_priv);
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int bpf_program__get_private(struct bpf_program *prog,
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void **ppriv);
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2015-11-03 11:21:05 +00:00
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const char *bpf_program__title(struct bpf_program *prog, bool needs_copy);
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2015-07-01 02:14:08 +00:00
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int bpf_program__fd(struct bpf_program *prog);
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2015-07-01 02:14:02 +00:00
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/*
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* We don't need __attribute__((packed)) now since it is
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* unnecessary for 'bpf_map_def' because they are all aligned.
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* In addition, using it will trigger -Wpacked warning message,
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* and will be treated as an error due to -Werror.
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*/
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struct bpf_map_def {
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unsigned int type;
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unsigned int key_size;
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unsigned int value_size;
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unsigned int max_entries;
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};
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bpf tools: Introduce 'bpf' library and add bpf feature check
This is the first patch of libbpf. The goal of libbpf is to create a
standard way for accessing eBPF object files. This patch creates
'Makefile' and 'Build' for it, allows 'make' to build libbpf.a and
libbpf.so, 'make install' to put them into proper directories.
Most part of Makefile is borrowed from traceevent.
Before building, it checks the existence of libelf in Makefile, and deny
to build if not found. Instead of throwing an error if libelf not found,
the error raises in a phony target "elfdep". This design is to ensure
'make clean' still workable even if libelf is not found.
Because libbpf requires 'kern_version' field set for 'union bpf_attr'
(bpfdep" is used for that dependency), Kernel BPF API is also checked
by intruducing a new feature check 'bpf' into tools/build/feature,
which checks the existence and version of linux/bpf.h. When building
libbpf, it searches that file from include/uapi/linux in kernel source
tree (controlled by FEATURE_CHECK_CFLAGS-bpf). Since it searches kernel
source tree it reside, installing of newest kernel headers is not
required, except we are trying to port these files to an old kernel.
To avoid checking that file when perf building, the newly introduced
'bpf' feature check doesn't added into FEATURE_TESTS and
FEATURE_DISPLAY by default in tools/build/Makefile.feature, but added
into libbpf's specific.
Signed-off-by: Wang Nan <wangnan0@huawei.com>
Acked-by: Alexei Starovoitov <ast@plumgrid.com>
Cc: Brendan Gregg <brendan.d.gregg@gmail.com>
Cc: Daniel Borkmann <daniel@iogearbox.net>
Cc: David Ahern <dsahern@gmail.com>
Cc: He Kuang <hekuang@huawei.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Kaixu Xia <xiakaixu@huawei.com>
Cc: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Zefan Li <lizefan@huawei.com>
Bcc: pi3orama@163.com
Link: http://lkml.kernel.org/r/1435716878-189507-4-git-send-email-wangnan0@huawei.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2015-07-01 02:13:51 +00:00
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#endif
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